March 1, 2009

They say Passiflora is a mild hallucinogen, which may explain why the South American missionaries who “discovered” the plant saw in it a crown of thorns, five stamens representing the five wounds of Christ, five petals and five sepals the ten apostles (excluding, handily, Judas and Peter) and three stigmas for the nails on the cross. But the stoned padres ignored a far more cogent proof of the existence of god close by. I write this from Thailand, while tasting passionfruit in full glory. What passes for it in Europe is usually a mean, shrunken shell containing a spoonful of grey snot that tastes like cheap fruit cocktail. In Thailand a bag of passionfruit (1 euro) fills the room with a fragrance that all the world’s perfumers would give their last quarter-ounce of vintage Iris Gris for.

The taste is unusually true to the smell, merely stronger, parfum to the smell’s eau de toilette. In the mouth the fruit, like a perfect Sauternes, has tremendous acidity to counterbalance the lushness of the flavor. But smell a Sauternes in the glass and you’d never know it was acid: sour is a taste, not a smell. Amazingly, as if it bestowed upon us an extra sense, passionfruit manages to smell sour. Fruit have personalities: peaches are generous, apples hale, pears aristocratic, apricots gentle, mangos grand, lychees peaceable, pineapple glitzy. Passionfruit is the impossibly pretty joker in the pack, perhaps the only fruit worthy of the strange phrase tutti frutti.

I imagine flavor chemists, on the walls of their student rooms, have posters of scantily clad papayas instead of Salma Hayek and Eva Mendes. Since 1977 and the identification of a sulfur-containing molecule called Oxane, the code of passionfruit has been partially cracked. Oxane is now used and abused in all tropical fruit fragrances and flavors. It is sensationally powerful and therefore cheap: a chemist colleague once told me that 100 grams accidentally spilled in the factory drains caused the surrounding English countryside to smell of the tropics for days. But, just as tying a sarong round your waist won’t turn Basel into Bali, Oxane is only part of the answer.

A thorough analysis of the molecules emitted by passionfruit done by the great firm of Haarmann and Reimer in 1998 revealed 180 different molecules never before seen, 47 of which are sulfur compounds, with smells ranging from rotten cabbage to blocked drains. The proximity of beauty to ugliness is never clearer than in tropical fruit. Perhaps because they have to compete with powerful smells of decay for the attention of birds, tropical fruit have decided to play dirty. Adding tiny amounts of rot on an otherwise conventional fruity smell is as invigorating as finding out that a theoretical physicist colleague was once a stripper. Try this at home: buy some sulfurous kala namak salt from an Indian shop, sprinkle it on tinned fruit salad, and send me a postcard from wherever you find yourself.